The present invention relates to ballistic missiles and, in particular, to methods for reducing the missile range errors arising because of velocity uncertainties.
As is known, the theoretical flight or trajectory of ballistic missiles can be predetermined accurately. In addition, the time of the missile flight normally is very closely controlled. Consequently, the so-called `nominal` position of the missile at any time in flight can be predicted. Such predictions, however, are not necessarily valid. For one reason, errors may occur in a trajectory due to velocity uncertainties. It is possible to plot a parameter for these position errors and such plots, known as `ballistic position error ellipses`, can be derived for each missile trajectory in a manner described by R. H. Frick, "Motion of Objects Ejected from an ICBM or a Satellite Vehicle", RM-1701, May 1, 1956, ad114192. Such ellipses have been used to predict the performance of the missile and to predetermine the probability of the effectiveness of the missile upon the intended target.